What are the clinical manifestations of Polymyalgia Rheumatica (PMR)?

Clinical Manifestations of Polymyalgia Rheumatica (PMR)

Polymyalgia rheumatica (PMR) presents primarily as acute, predominantly bilateral shoulder and/or hip pain with morning stiffness and possible swelling of the hands and knees. 1

Cardinal Clinical Features

• Pain and Stiffness Distribution:

  • Bilateral proximal aching in shoulders and upper arms 1, 2
  • Hip girdle and thigh involvement 2
  • Neck pain 2
  • Lower back discomfort 3
  • Morning stiffness lasting >45 minutes 3

• Systemic Manifestations:

  • Constitutional symptoms (fatigue, malaise, low-grade fever) 2
  • Weight loss 2
  • Depression and sleep disturbances due to pain 2

Laboratory Findings

• Inflammatory Markers:

  • Elevated erythrocyte sedimentation rate (ESR) - typically >40 mm/hr 1, 2
  • Elevated C-reactive protein (CRP) 1, 2
  • Note: ESR/CRP may occasionally be normal in some PMR cases 1

• Other Laboratory Features:

  • Normocytic anemia 2
  • Negative rheumatoid factor (RF) 1, 2
  • Negative anti-cyclic citrullinated peptide (anti-CCP) antibodies 1, 2
  • Normal creatine kinase (CK) levels (important to distinguish from myositis) 1, 2

Imaging Findings

• Ultrasound:

  • Subdeltoid bursitis 2
  • Biceps tenosynovitis 2
  • Glenohumeral synovitis 2
  • Trochanteric bursitis 2

• MRI:

  • Periarticular inflammation 2
  • Bursitis 2
  • Tenosynovitis 2

Diagnostic Clues

• Rapid Response to Glucocorticoids:

  • Dramatic improvement within 24-72 hours of starting low-dose prednisone (12.5-25 mg/day) 1, 2, 4
  • This response is considered a diagnostic feature but is not specific to PMR 5

• Age Consideration:

  • Most common in patients >50 years of age 2, 3
  • Peak incidence in the eighth decade 5
  • Younger patients with PMR-like symptoms require more extensive evaluation 2

Associated Conditions

• Giant Cell Arteritis (GCA):
  • Present in 10-30% of PMR patients 2
  • Must be ruled out, especially in patients with headache, scalp tenderness, jaw claudication, or visual disturbances 1, 2

Important Differential Diagnoses

• Rheumatoid arthritis (especially late-onset) 2
• Inflammatory myopathies 2
• Spondyloarthropathies 2
• Systemic lupus erythematosus 2
• Malignancy-associated syndromes 2
• Infections 2
• Immune checkpoint inhibitor-related PMR-like syndrome 2
• Parkinson's disease (can mimic stiffness) 1
• Osteoarthritis of shoulder or cervical spine 1
• Rotator cuff disease 1
• Fibromyalgia 1

Prognostic Factors

• Higher Risk of Relapse:
  • Female sex 1
  • High acute phase reactants at baseline 1
  • Peripheral arthritis 1
  • Persistently elevated inflammatory markers despite treatment 1

Clinical Pearls

• PMR is the second most common inflammatory rheumatic disease in the elderly after rheumatoid arthritis 6
• Symptoms typically develop over weeks to months 2
• Patients often have difficulty with daily activities like rising from bed, getting dressed, or combing hair 2
• The condition can significantly impact quality of life due to pain and functional limitations 7
• Atypical presentations warrant rheumatology referral, especially in patients <60 years 2

Remember that PMR diagnosis remains clinical, based on the characteristic pattern of symptoms, elevated inflammatory markers, exclusion of mimicking conditions, and response to glucocorticoids. No single test is diagnostic for PMR.